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When to Plant Microgreens in La Plata County, CO

La Plata County, Colorado Zone 6a May

May to-do list for La Plata County, Colorado

May is a pivotal month for La Plata County, Colorado gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost May 31
Avg. first frost September 21
Soil temp (4") 44°F
Watering High
Pest pressure Low
Daylight 14 hrs
  1. Transplant microgreens outside

    Your last frost (May 31) has passed. These warm-season crops can handle outdoor soil now.

  2. Direct-sow microgreens

    Sow every 2 weeks for a continuous harvest. A single big planting means a single big glut.

Before June arrives, get these ready
  • First harvests: microgreens

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Microgreens are young seedlings of vegetables and herbs harvested at the cotyledon or first true leaf stage. They pack concentrated flavors and nutrients in a tiny package.

La Plata County, Colorado is in USDA Zone 6a. The average last spring frost is May 31 and the first fall frost is September 21, giving you a growing season of approximately 113 days.

At an elevation of 5,246 feet, La Plata County receives approximately 14.9 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Microgreens to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Microgreens successfully. Mulch heavily to conserve soil moisture.

La Plata County, CO (Zone 6a) Short season
113 days
Last Spring Frost May 31
113 growing days
First Fall Frost September 21

La Plata County Soil Profile

Soil Type

Loam

Soil pH

6.2-7.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (84 days to spare)
Start indoors: Apr 9 Transplant: May 14 🍅 Harvest: May 21 – Jun 18
Recommended (50%) ✓ Fits season (78 days to spare)
Start indoors: Apr 26 Transplant: May 31 🍅 Harvest: Jun 7 – Jul 5
Safe Start (90%) ✓ Fits season (73 days to spare)
Start indoors: May 22 Transplant: Jun 26 🍅 Harvest: Jul 3 – Jul 31

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Soil Compatibility in La Plata County

How your county's soil matches Microgreens's growing requirements.

Soil pH

Your soil pH (6.2–7.9) is more alkaline than Microgreens prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in La Plata County is excellent for Microgreens — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.7%). Annual compost additions will help Microgreens.

How to Plant Microgreens

0.5"
Planting Depth
2"
Between Plants
6"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Microgreens

22
successive plantings in your 113-day season

Sow every 0.7 weeks. Last sowing by Aug 31 to harvest before frost.

For a dedicated fall crop, sow by Jul 13.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 538 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Microgreens

Microgreens needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Microgreens Needs Rainfall You Supplement Action
Jan 0.9" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 1.2" 0" ❄️ Dormant
Apr 1.6" 0" ❄️ Dormant
May 4.3" 1.6" 2.7" 🚿 Regular watering
Jun 4.3" 0.9" 3.4" 🚿 Regular watering
Jul 4.3" 1.4" 2.9" 🚿 Regular watering
Aug 4.3" 1.5" 2.8" 🚿 Regular watering
Sep 4.3" 1.3" 3" 🚿 Regular watering
Oct 1.5" 0" ❄️ Dormant
Nov 1" 0" ❄️ Dormant
Dec 1" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in La Plata County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Microgreens Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Microgreens needs ~172 GDD — county provides 1,384 GDD Excellent fit

Microgreens Planting Timeline — La Plata County, CO

Microgreens Planting Calendar

Activity When Date Range
Start Indoors April 26 Apr 26 – May 10
Transplant Outdoors May 31 May 31 – Jun 14
Direct Sow May 17 May 17 – Jun 7
Harvest June 7 Jun 7 – Jul 5
Fall Sowing July 13 Jul 13 – Jul 27

Plant 0.5" deep · 2" apart · Rows 6" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors
May Start Indoors Transplant Outdoors Direct Sow
June Transplant Outdoors Direct Sow Harvest
July Fall Sowing Harvest
August
September
October
November
December

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

7–21 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 6a

📆 Growing Season

113 days in La Plata County

Growing Tips for Microgreens in La Plata County

Direct sow Microgreens outdoors after May 31 in La Plata County when soil has warmed and frost danger has passed.

Your generous 113.0-day season in La Plata County allows multiple plantings of Microgreens. Sow every 3.0 days for continuous harvest.

La Plata County receives only 15" of rain annually. Microgreens needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Sow seeds densely on shallow trays of moist growing medium. Cover until germination, then provide light. Harvest with scissors when 1-3 inches tall. Grow year-round indoors.

Frequently Asked Questions

When should I plant Microgreens in La Plata County, CO?

La Plata County is in Zone 6a with an average last frost of May 31. Plan your Microgreens planting based on this frost date — see the calendar above for exact timing.

What planting zone is La Plata County, CO?

La Plata County, Colorado is in USDA Hardiness Zone 6a. The average last spring frost is May 31 and first fall frost is September 21.

🌱

Your La Plata County Garden Planner — Free

A 24-page printable planner built for La Plata County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for La Plata County, CO. Local conditions may vary. Last updated: May 2026.

Sources & credits

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